Course: Combined Science + Separate Physics | 20 questions | g = 9.8 N/kg | ← All quizzes
Write A, B, C or D for each question, then tap Show answer to mark it.
Q1 (F, recall) Which of these is an energy store?
A. Light
B. Sound
C. Chemical
D. Electrical
Show answer
✅ C. Chemical
The eight stores are kinetic, gravitational potential, elastic potential, thermal, chemical, magnetic, electrostatic and nuclear.
Examiner tip: light, sound and electrical are ways energy is transferred (pathways), not stores.
Q2 (F, definition) What is the specific heat capacity of a substance?
A. The energy needed to melt 1 kg of the substance
B. The energy needed to raise the temperature of 1 kg of the substance by 1 °C
C. The temperature a substance reaches when 1 J of energy is supplied
D. The energy stored in 1 kg of the substance
Show answer
✅ B
Examiner tip: A describes specific latent heat of fusion, which is a common mix-up.
Q3 (F, calculation) A runner of mass 60 kg runs at 5.0 m/s. What is her kinetic energy?
A. 150 J
B. 300 J
C. 1500 J
D. 750 J
Show answer
✅ D. 750 J
F: Eₖ = ½ m v²
I: Eₖ = 0.5 × 60 × 5.0²
F: Eₖ = 0.5 × 60 × 25
A: 750 J
Examiner tip: 1500 J means you forgot the ½; 150 J means you forgot to square the speed.
Q4 (F, calculation) A 2.0 kg book is lifted 1.5 m onto a shelf. How much gravitational potential energy does it gain?
A. 3.0 J
B. 13 J
C. 29 J
D. 290 J
Show answer
✅ C. 29 J
F: Eₚ = m g h
I: Eₚ = 2.0 × 9.8 × 1.5
A: 29.4 J = 29 J (2 s.f.)
Examiner tip: 3.0 J means g was left out.
Q5 (F, calculation) A motor transfers 4800 J in 60 s. What is its power?
A. 0.0125 W
B. 80 W
C. 4860 W
D. 288 000 W
Show answer
✅ B. 80 W
F: P = E ÷ t
I: P = 4800 ÷ 60
A: 80 W
Examiner tip: power is energy per second, so divide by the time.
Q6 (F, calculation) A lamp is supplied with 500 J and transfers 350 J usefully. What is its efficiency?
A. 0.70
B. 0.30
C. 1.43
D. 150 J
Show answer
✅ A. 0.70 (70%)
F: efficiency = useful output energy ÷ total input energy
I: efficiency = 350 ÷ 500
A: 0.70
Examiner tip: efficiency can never be more than 1 (100%), and it has no unit.
Q7 (F, application) What happens to the energy wasted by an electric kettle?
A. It is destroyed
B. It is stored in the kettle’s chemical store
C. It turns into electrical energy
D. It is dissipated to the thermal store of the surroundings
Show answer
✅ D
Energy can’t be destroyed. Wasted energy spreads out, usually heating the surroundings.
Examiner tip: never write that energy is “lost” or “used up”. Say it is dissipated.
Q8 (F, recall) Which of these is a renewable energy resource?
A. Coal
B. Wind
C. Natural gas
D. Nuclear fuel
Show answer
✅ B. Wind
A renewable resource is one that is being (or can be) replenished as it is used.
Examiner tip: nuclear fuel is non-renewable, even though it produces no carbon dioxide when used.
Q9 (F/H, definition) Which statement describes the principle of conservation of energy?
A. Energy is always transferred usefully
B. Energy is lost when it is transferred
C. Energy can be transferred, stored or dissipated, but cannot be created or destroyed
D. The total energy of a system always increases
Show answer
✅ C
Examiner tip: learn this word for word. It is a common 1-mark definition.
Q10 (F/H, calculation) 0.50 kg of water is heated from 20 °C to 60 °C. The specific heat capacity of water is 4200 J/kg °C. How much energy is transferred?
A. 42 000 J
B. 84 000 J
C. 126 000 J
D. 8400 J
Show answer
✅ B. 84 000 J
F: ΔE = m c Δθ
I: ΔE = 0.50 × 4200 × (60 − 20)
F: ΔE = 0.50 × 4200 × 40
A: 84 000 J
Examiner tip: 126 000 J comes from using 60 °C instead of the temperature change.
Q11 (F/H, calculation) A spring with a spring constant of 200 N/m is stretched by 5.0 cm. How much elastic potential energy is stored?
A. 0.50 J
B. 5.0 J
C. 2500 J
D. 0.25 J
Show answer
✅ D. 0.25 J
Convert: 5.0 cm = 0.050 m
F: Eₑ = ½ k e²
I: Eₑ = 0.5 × 200 × 0.050²
A: 0.25 J
Examiner tip: 2500 J comes from leaving the extension in cm. Always convert to metres.
Q12 (F/H, practical) In the specific heat capacity practical, why is the metal block wrapped in insulation?
A. To make the block heat up more slowly
B. So the thermometer reads accurately
C. To reduce energy transfer to the surroundings
D. To increase the mass of the block
Show answer
✅ C
Less energy is wasted heating the surroundings, so more of the energy supplied raises the block’s temperature. This makes the value of c more accurate.
Examiner tip: energy lost to the surroundings makes the calculated value of c too high.
Q13 (F/H, graph) A student heats a 1.0 kg metal block. Her graph of temperature against energy supplied is a straight line from 20 °C at 0 J to 30 °C at 9000 J. What is the specific heat capacity of the metal?
A. 900 J/kg °C
B. 300 J/kg °C
C. 9000 J/kg °C
D. 90 J/kg °C
Show answer
✅ A. 900 J/kg °C
Read from the graph: ΔE = 9000 J, Δθ = 30 − 20 = 10 °C
F: ΔE = m c Δθ
I: 9000 = 1.0 × c × 10
F: c = 9000 ÷ 10
A: 900 J/kg °C
Examiner tip: 300 comes from using 30 °C instead of the change of 10 °C.
Q14 (F/H, application) Which change would make a house cool down most slowly?
A. Thinner walls with a higher thermal conductivity
B. Thinner walls with a lower thermal conductivity
C. Thicker walls with a higher thermal conductivity
D. Thicker walls with a lower thermal conductivity
Show answer
✅ D
The rate of energy transfer through a wall decreases with greater thickness and lower thermal conductivity.
Examiner tip: use the phrase “thermal conductivity” and link it to the rate of energy transfer.
Q15 (H, calculation) A 0.20 kg ball has 40 J of kinetic energy. What is its speed?
A. 400 m/s
B. 20 m/s
C. 14 m/s
D. 200 m/s
Show answer
✅ B. 20 m/s
F: Eₖ = ½ m v²
I: 40 = 0.5 × 0.20 × v²
F: v² = 40 ÷ 0.10 = 400, so v = √400
A: 20 m/s
Examiner tip: 400 m/s means you forgot the square root at the end.
Q16 (H, calculation) A stone is dropped from a height of 5.0 m. Air resistance can be ignored. What is its speed just before it hits the ground?
A. 98 m/s
B. 49 m/s
C. 9.9 m/s
D. 7.0 m/s
Show answer
✅ C. 9.9 m/s
GPE lost = KE gained, so m g h = ½ m v² (the mass cancels)
I: 9.8 × 5.0 = 0.5 × v²
F: v² = 2 × 49 = 98, so v = √98
A: 9.9 m/s
Examiner tip: when no mass is given, use energy conservation – the mass cancels out.
Q17 (H, calculation) A motor is 80% efficient. Its input power is 2.5 kW. What is its useful output power?
A. 2000 W
B. 3125 W
C. 500 W
D. 200 W
Show answer
✅ A. 2000 W
Convert: 2.5 kW = 2500 W; 80% = 0.80
F: efficiency = useful power output ÷ total power input
I: 0.80 = P ÷ 2500
F: P = 0.80 × 2500
A: 2000 W
Examiner tip: 3125 W is impossible – useful output can never be more than the input.
Q18 (F/H, application) Why can’t solar panels alone supply electricity reliably?
A. They are non-renewable
B. They produce carbon dioxide
C. They are very expensive to run
D. Their output depends on the time of day and the weather
Show answer
✅ D
Solar panels produce no electricity at night and less on cloudy days, so supply can’t be guaranteed to meet demand.
Examiner tip: when comparing resources, give a specific reason like this rather than just saying “unreliable”.
Q19 (F/H, graph) A Sankey diagram for a lamp shows 200 J in, 20 J out as light and 180 J out as thermal energy. What is the efficiency of the lamp?
A. 90%
B. 10%
C. 20%
D. 11%
Show answer
✅ B. 10%
F: efficiency = useful output ÷ total input
I: efficiency = 20 ÷ 200 = 0.10
A: 0.10 × 100 = 10%
Examiner tip: the useful output for a lamp is light. 90% is the wasted fraction.
Q20 (H, calculation) A 2.0 kg block is heated with 18 000 J of energy. Its temperature rises from 15 °C to 35 °C. What is the specific heat capacity of the block?
A. 900 J/kg °C
B. 257 J/kg °C
C. 450 J/kg °C
D. 45 000 J/kg °C
Show answer
✅ C. 450 J/kg °C
F: ΔE = m c Δθ
I: 18 000 = 2.0 × c × 20
F: c = 18 000 ÷ 40
A: 450 J/kg °C
Examiner tip: substitute first, then rearrange. 257 comes from using 35 °C instead of the change of 20 °C.
Your score
Add up your marks out of 20 and multiply by 5 to get a percentage. Rough guide (not an official grade): 18–20 excellent, grade 8–9 standard | 14–17 grade 6–7 | 10–13 grade 4–5 | under 10 revise the notes and try again.
Answer key (for teachers and printing)
1 C 2 B 3 D 4 C 5 B 6 A 7 D 8 B 9 C 10 B 11 D 12 C 13 A 14 D 15 B 16 C 17 A 18 D 19 B 20 C
Revise: Energy topic page | Fill the gaps: Energy | Which equation? Energy
